:root{
  --board-1:#0c2a1c;
  --board-2:#173d28;
  --chalk-white:#f4f1e6;
  --chalk-dim:#cfd8cc;
  --chalk-yellow:#f2cd5c;
  --chalk-coral:#ef8b7a;
  --chalk-blue:#8fc7d9;
  --wood:#5b3a24;
  --shadow:rgba(0,0,0,.35);
  --radius:10px;
}
*{box-sizing:border-box;}
html,body{margin:0;padding:0;height:100%;}
body{
  font-family:'Work Sans',sans-serif;
  color:var(--chalk-white);
  background:
    radial-gradient(ellipse at 20% -10%, rgba(255,255,255,0.05), transparent 45%),
    linear-gradient(160deg,var(--board-2),var(--board-1) 60%);
  min-height:100vh;
  overflow-x:hidden;
}
body::before{
  content:"";
  position:fixed; inset:0;
  background-image:
    radial-gradient(rgba(255,255,255,.035) 1px, transparent 1px),
    radial-gradient(rgba(255,255,255,.025) 1px, transparent 1px);
  background-size: 3px 3px, 7px 7px;
  background-position: 0 0, 2px 3px;
  pointer-events:none;
  z-index:0;
}
.frame{
  position:relative;
  z-index:1;
  border:14px solid var(--wood);
  border-image: linear-gradient(160deg,#6b4529,#3f2717) 1;
  min-height:100vh;
  box-shadow: inset 0 0 40px var(--shadow), 0 0 60px var(--shadow);
}
.chalk-font{ font-family:'Caveat',cursive; }

/* landing */
.landing{
  min-height:100vh; display:flex; align-items:center; justify-content:center; text-align:center; padding:20px;
}
.landing-inner{ max-width:480px; }
.landing-title{ font-size:4.2rem; color:var(--chalk-white); margin:0; text-shadow:0 0 20px rgba(244,241,230,.15); }
.landing-title span{ color:var(--chalk-yellow); }
.landing-sub{ color:var(--chalk-dim); font-size:1.05rem; margin:10px 0 30px; line-height:1.6; }
.google-btn-holder{ display:flex; justify-content:center; margin-bottom:18px; min-height:44px; }
.consent-row{ display:flex; align-items:flex-start; gap:10px; text-align:left; background:rgba(255,255,255,.03); border:1px solid rgba(244,241,230,.15); border-radius:8px; padding:12px 14px; margin-bottom:16px; cursor:pointer; }
.consent-row input{ margin-top:3px; flex-shrink:0; width:16px; height:16px; accent-color:var(--chalk-yellow); cursor:pointer; }
.consent-row span{ font-size:.78rem; color:var(--chalk-dim); line-height:1.5; }
.consent-hint{ color:var(--chalk-dim); font-size:.78rem; margin:0; }
.landing-note{ color:var(--chalk-dim); font-size:.78rem; }

/* header */
header{
  padding:22px 32px 14px;
  display:flex; align-items:center; justify-content:space-between; flex-wrap:wrap; gap:14px;
  border-bottom:2px dashed rgba(244,241,230,.18);
}
header h1{ font-family:'Caveat',cursive; font-weight:700; font-size:2.6rem; margin:0; color:var(--chalk-white); }
header h1 span{ color:var(--chalk-yellow); }
header p{ margin:2px 0 0; color:var(--chalk-dim); font-size:.85rem; }
.header-right{ display:flex; align-items:center; gap:12px; flex-wrap:wrap; }

.user-chip{ display:flex; align-items:center; gap:8px; background:rgba(255,255,255,.04); border:1px solid rgba(244,241,230,.16); border-radius:30px; padding:5px 6px 5px 5px; }
.user-chip img{ width:28px; height:28px; border-radius:50%; }
.user-chip span{ font-size:.82rem; }

.xp-badge{ display:flex; align-items:center; gap:9px; background:rgba(242,205,92,.08); border:1px solid rgba(242,205,92,.3); border-radius:30px; padding:7px 16px 7px 12px; transition:.2s; }

.premium-btn{ background:linear-gradient(135deg, #f2cd5c, #ef8b7a); color:#2a1205; border-color:transparent; font-weight:700; }
.premium-btn:hover{ filter:brightness(1.08); }
.premium-chip{
  display:inline-flex; align-items:center; gap:6px; font-size:.78rem; font-weight:700;
  background:linear-gradient(135deg, rgba(242,205,92,.18), rgba(239,139,122,.18));
  border:1px solid rgba(242,205,92,.4); color:var(--chalk-yellow);
  padding:7px 14px; border-radius:30px;
}
.xp-badge #xpLevelIcon{ font-size:1.2rem; }
.xp-badge .xp-text{ display:flex; flex-direction:column; line-height:1.2; }
.xp-badge #xpLevelTitle{ font-family:'Caveat',cursive; font-size:1.05rem; color:var(--chalk-yellow); font-weight:700;}
.xp-badge #xpAmount{ font-size:.65rem; color:var(--chalk-dim); }
.xp-badge.bump{ animation:xpBump .4s ease; }
@keyframes xpBump{ 0%{transform:scale(1);} 40%{transform:scale(1.12);} 100%{transform:scale(1);} }

/* modal */
.modal-overlay{ display:none; position:fixed; inset:0; z-index:50; background:rgba(4,12,8,.72); align-items:center; justify-content:center; padding:20px; }
.modal-overlay.open{ display:flex; }
.modal{ background:linear-gradient(160deg,var(--board-2),var(--board-1)); border:1px solid rgba(244,241,230,.2); border-radius:12px; padding:26px 28px; max-width:440px; width:100%; box-shadow:0 20px 60px rgba(0,0,0,.5); }
.modal h3{ font-size:1.7rem; color:var(--chalk-yellow); margin:0 0 10px; }
.modal p{ font-size:.85rem; color:var(--chalk-dim); line-height:1.6; margin:0 0 12px;}
.modal ol{ font-size:.82rem; color:var(--chalk-dim); padding-left:1.2em; line-height:1.9; margin:0 0 16px;}
.modal a{ color:var(--chalk-blue); }
.modal input{ width:100%; background:rgba(255,255,255,.05); border:1px solid rgba(244,241,230,.25); border-radius:7px; padding:10px 12px; color:var(--chalk-white); font-family:'JetBrains Mono',monospace; font-size:.82rem; margin-bottom:14px; }
.modal input:focus{ outline:none; border-color:var(--chalk-yellow); }
.modal-actions{ display:flex; justify-content:flex-end; gap:10px; }
.key-banner{ margin:0 32px 0; padding:12px 16px; border-radius:8px; background:rgba(239,139,122,.12); border:1px solid rgba(239,139,122,.35); font-size:.82rem; display:flex; align-items:center; justify-content:space-between; gap:12px; }

/* toasts / confetti */
.toast-container{ position:fixed; top:20px; right:20px; z-index:80; display:flex; flex-direction:column; gap:8px; align-items:flex-end; pointer-events:none; }
.toast{ font-family:'Caveat',cursive; font-size:1.25rem; font-weight:700; background:rgba(23,61,40,.95); border:1px solid rgba(242,205,92,.4); color:var(--chalk-yellow); padding:8px 18px; border-radius:8px; box-shadow:0 8px 24px rgba(0,0,0,.4); animation:toastIn .35s ease, toastOut .4s ease 1.8s forwards; }
@keyframes toastIn{ from{ opacity:0; transform:translateY(-10px) rotate(-2deg);} to{ opacity:1; transform:translateY(0) rotate(-1deg);} }
@keyframes toastOut{ from{ opacity:1; } to{ opacity:0; transform:translateY(-6px);} }
.confetti-layer{ position:fixed; inset:0; z-index:70; pointer-events:none; overflow:hidden; }
.confetti-bit{ position:absolute; top:-20px; width:8px; height:14px; border-radius:2px; animation:confettiFall linear forwards; }
@keyframes confettiFall{ to{ transform:translateY(110vh) rotate(720deg); opacity:.2; } }

/* layout */
.layout{ display:grid; grid-template-columns: 300px 1fr; min-height:calc(100vh - 92px); }
@media (max-width: 860px){ .layout{ grid-template-columns: 1fr; } .sidebar{ border-right:none; border-bottom:2px dashed rgba(244,241,230,.18); } }

.sidebar{ padding:20px 18px; border-right:2px dashed rgba(244,241,230,.18); display:flex; flex-direction:column; gap:14px; }
.upload-zone{ border:2px dashed rgba(244,241,230,.35); border-radius:var(--radius); padding:22px 14px; text-align:center; cursor:pointer; transition:.2s; background:rgba(255,255,255,.02); }
.upload-zone:hover, .upload-zone.drag{ border-color:var(--chalk-yellow); background:rgba(242,205,92,.06); }
.upload-zone svg{ width:30px; height:30px; opacity:.8; margin-bottom:6px; }
.upload-zone .t1{ font-family:'Caveat',cursive; font-size:1.4rem; color:var(--chalk-yellow);}
.upload-zone .t2{ font-size:.72rem; color:var(--chalk-dim); margin-top:4px;}
#fileInput{ display:none; }

.upload-actions{ display:flex; flex-direction:column; gap:8px; }
.upload-btn{
  font-family:'Work Sans',sans-serif; font-size:.8rem; font-weight:600;
  padding:10px 14px; border-radius:8px; cursor:pointer; text-align:left;
  border:1px solid rgba(244,241,230,.18); background:rgba(255,255,255,.03); color:var(--chalk-white);
  transition:.15s;
}
.upload-btn:hover{ background:rgba(255,255,255,.08); border-color:rgba(244,241,230,.35); }

.topics{ display:flex; flex-direction:column; gap:8px; overflow-y:auto; max-height:56vh;}
.topic-card{ position:relative; background:rgba(255,255,255,.03); border:1px solid rgba(244,241,230,.12); border-radius:8px; padding:10px 12px; cursor:pointer; transition:.15s; display:flex; align-items:center; gap:10px; }
.topic-card:hover{ background:rgba(255,255,255,.06); }
.topic-card.active{ border-color:var(--chalk-yellow); background:rgba(242,205,92,.09); }
.topic-card .dot{ width:8px; height:8px; border-radius:50%; background:var(--chalk-dim); flex-shrink:0; }
.topic-card.active .dot{ background:var(--chalk-yellow); box-shadow:0 0 6px var(--chalk-yellow);}
.topic-card .name{ font-size:.86rem; font-weight:500; overflow:hidden; text-overflow:ellipsis; white-space:nowrap; flex:1; }
.topic-card .del{ opacity:0; background:none; border:none; color:var(--chalk-coral); cursor:pointer; font-size:.9rem; padding:2px 4px; }
.topic-card:hover .del{ opacity:.7; }
.topic-card .del:hover{ opacity:1; }
.sidebar-foot{ margin-top:auto; padding-top:12px; border-top:2px dashed rgba(244,241,230,.18); font-size:.7rem; color:var(--chalk-dim); line-height:1.5; }

main{ padding:26px 34px 40px; overflow-y:auto; }
.empty-state{ height:70vh; display:flex; flex-direction:column; align-items:center; justify-content:center; text-align:center; color:var(--chalk-dim); }
.empty-state .chalk-font{ font-size:2.2rem; color:var(--chalk-white); margin-bottom:6px;}
.empty-state svg{ width:64px; opacity:.5; margin-bottom:14px; }

.topic-header{ display:flex; align-items:center; justify-content:space-between; gap:14px; margin-bottom:18px; flex-wrap:wrap; }
.topic-header h2{ font-family:'Caveat',cursive; font-size:2.1rem; margin:0; color:var(--chalk-yellow); font-weight:700; }
.actions{ display:flex; gap:10px; }
.btn{ font-family:'Work Sans',sans-serif; font-size:.8rem; font-weight:600; padding:9px 16px; border-radius:7px; cursor:pointer; border:1px solid rgba(244,241,230,.25); background:rgba(255,255,255,.04); color:var(--chalk-white); transition:.15s; display:flex; align-items:center; gap:6px; }
.btn:hover{ background:rgba(255,255,255,.1); border-color:var(--chalk-white); }
.btn.primary{ background:var(--chalk-yellow); color:#2a2205; border-color:var(--chalk-yellow); }
.btn.primary:hover{ filter:brightness(1.08); }
.btn:disabled{ opacity:.4; cursor:not-allowed; }

.loading-row{ display:flex; align-items:center; gap:10px; color:var(--chalk-dim); font-size:.85rem; padding:20px 0; }
.chalk-spin{ width:16px; height:16px; border-radius:50%; border:2px solid rgba(244,241,230,.25); border-top-color:var(--chalk-yellow); animation:spin 0.8s linear infinite; }
@keyframes spin{ to{ transform:rotate(360deg);} }

.explanation{ background:rgba(255,255,255,.025); border:1px solid rgba(244,241,230,.12); border-radius:var(--radius); padding:26px 30px; line-height:1.75; font-size:.98rem; }
.explanation h1,.explanation h2,.explanation h3{ font-family:'Caveat',cursive; color:var(--chalk-yellow); font-weight:700; border-bottom:1px dashed rgba(244,241,230,.2); padding-bottom:6px; }
.explanation h1{ font-size:1.9rem; }
.explanation h2{ font-size:1.6rem; margin-top:26px;}
.explanation h3{ font-size:1.3rem; color:var(--chalk-blue); border-bottom:none;}
.explanation strong{ color:var(--chalk-yellow); }
.explanation code{ background:rgba(0,0,0,.3); padding:2px 6px; border-radius:4px; font-family:'JetBrains Mono',monospace; font-size:.85em; color:var(--chalk-blue); }
.explanation pre{ background:rgba(0,0,0,.3); padding:14px; border-radius:8px; overflow-x:auto; }
.explanation ul,.explanation ol{ padding-left:1.4em; }
.explanation li{ margin-bottom:6px; }
.explanation table{ border-collapse:collapse; width:100%; margin:14px 0; font-size:.9em;}
.explanation th,.explanation td{ border:1px solid rgba(244,241,230,.2); padding:8px 10px; text-align:left;}
.explanation th{ background:rgba(255,255,255,.05); color:var(--chalk-yellow); }

.chat-section{ margin-top:30px; }
.chat-section h3{ font-family:'Caveat',cursive; font-size:1.6rem; color:var(--chalk-blue); margin-bottom:10px;}
.chat-log{ display:flex; flex-direction:column; gap:12px; margin-bottom:14px; }
.msg{ max-width:78%; padding:11px 15px; border-radius:10px; font-size:.9rem; line-height:1.55; }
.msg.user{ align-self:flex-end; background:rgba(242,205,92,.14); border:1px solid rgba(242,205,92,.3); border-bottom-right-radius:2px; }
.msg.ai{ align-self:flex-start; background:rgba(255,255,255,.04); border:1px solid rgba(244,241,230,.12); border-bottom-left-radius:2px; }
.chat-input-row{ display:flex; gap:10px; }
.chat-input-row input{ flex:1; background:rgba(255,255,255,.04); border:1px solid rgba(244,241,230,.2); border-radius:8px; padding:11px 14px; color:var(--chalk-white); font-family:'Work Sans',sans-serif; font-size:.9rem; }
.chat-input-row input:focus{ outline:none; border-color:var(--chalk-yellow); }

.quiz{ margin-top:30px; }
.quiz h3{ font-family:'Caveat',cursive; font-size:1.6rem; color:var(--chalk-coral); margin-bottom:14px;}
.streak-chip{ display:inline-flex; align-items:center; gap:5px; font-family:'Caveat',cursive; font-size:1.1rem; color:var(--chalk-coral); margin-left:10px; }
.q-card{ background:rgba(255,255,255,.025); border:1px solid rgba(244,241,230,.12); border-radius:10px; padding:16px 18px; margin-bottom:14px; }
.q-card .qtext{ font-weight:600; margin-bottom:10px; font-size:.92rem;}
.q-opt{ display:block; width:100%; text-align:left; padding:9px 12px; margin-bottom:7px; border-radius:7px; border:1px solid rgba(244,241,230,.18); background:rgba(255,255,255,.02); color:var(--chalk-white); cursor:pointer; font-family:'Work Sans',sans-serif; font-size:.85rem; transition:.15s; }
.q-opt:hover{ background:rgba(255,255,255,.07); }
.q-opt.correct{ border-color:#7cc98f; background:rgba(124,201,143,.15); }
.q-opt.wrong{ border-color:var(--chalk-coral); background:rgba(239,139,122,.15); }
.q-opt:disabled{ cursor:default; }
.quiz-summary{ text-align:center; padding:28px 20px; margin-top:6px; background:rgba(255,255,255,.03); border:1px solid rgba(244,241,230,.15); border-radius:12px; }
.quiz-summary .score{ font-family:'Caveat',cursive; font-size:3rem; font-weight:700; color:var(--chalk-yellow); line-height:1; }
.quiz-summary .msg{ font-size:1.05rem; margin-top:6px; }
.quiz-summary .sub{ font-size:.8rem; color:var(--chalk-dim); margin-top:6px; }

::-webkit-scrollbar{ width:9px; }
::-webkit-scrollbar-thumb{ background:rgba(244,241,230,.15); border-radius:6px; }
::-webkit-scrollbar-track{ background:transparent; }

/* ═══════════ MOBİL UYUM ═══════════ */
@media (max-width: 600px){
  .frame{ border-width:8px; }
  header{ padding:16px 16px 12px; }
  header h1{ font-size:2rem; }
  header p{ font-size:.75rem; }
  .header-right{ width:100%; justify-content:space-between; gap:8px; }
  .xp-badge{ padding:6px 10px 6px 8px; }
  .xp-badge #xpLevelTitle{ font-size:.9rem; }
  .xp-badge #xpAmount{ font-size:.6rem; }
  .btn{ padding:8px 12px; font-size:.75rem; }
  .user-chip span{ display:none; }
  .user-chip img{ width:24px; height:24px; }

  .landing-title{ font-size:2.6rem; }
  .landing-sub{ font-size:.9rem; }
  .consent-row{ padding:10px 12px; }
  .consent-row span{ font-size:.72rem; }

  .key-banner{ margin:0 16px; flex-direction:column; align-items:flex-start; gap:8px; }
  .modal{ padding:20px 18px; }
  .modal h3{ font-size:1.4rem; }

  .sidebar{ padding:14px 14px; }
  .topics{ max-height:34vh; }
  main{ padding:16px 16px 30px; }

  .topic-header{ flex-direction:column; align-items:flex-start; gap:10px; }
  .topic-header h2{ font-size:1.7rem; }
  .actions{ width:100%; }
  .actions .btn{ flex:1; justify-content:center; }

  .explanation{ padding:18px 16px; font-size:.92rem; }
  .explanation h1{ font-size:1.5rem; }
  .explanation h2{ font-size:1.3rem; }
  .explanation table{ display:block; overflow-x:auto; white-space:nowrap; }

  .msg{ max-width:90%; font-size:.85rem; }
  .chat-input-row{ flex-direction:column; }
  .chat-input-row .btn{ width:100%; justify-content:center; }

  .q-card{ padding:12px 14px; }
  .quiz-summary .score{ font-size:2.2rem; }

  .toast-container{ top:10px; right:10px; left:10px; align-items:stretch; }
  .toast{ text-align:center; }
}

@media (max-width: 380px){
  header h1{ font-size:1.7rem; }
  .xp-badge .xp-text{ display:none; }
  .landing-title{ font-size:2.1rem; }
}